Which of the following statements regarding the Salmonella bacterium is correct?

• A. Salmonella is a Gram-negative, rod-shaped bacterium commonly associated with foodborne illnesses.
• B. Salmonella produces oxygen during photosynthesis.
• C. Salmonella is an obligate anaerobe that cannot survive in the presence of oxygen.
• D. Salmonella is a Gram-positive, cocci-shaped bacterium found primarily in soil.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the basic characteristics of Salmonella, which is a genus of bacteria known to cause foodborne illnesses.
2. Step 2: Recall that Salmonella is classified as a Gram-negative bacterium, meaning it has a thin peptidoglycan layer and an outer membrane, which affects its staining properties and antibiotic susceptibility.
3. Step 3: Recognize the shape of Salmonella cells; they are rod-shaped (bacilli), not spherical (cocci).
4. Step 4: Consider the oxygen requirements of Salmonella. It is a facultative anaerobe, meaning it can survive with or without oxygen, so it is not an obligate anaerobe.
5. Step 5: Eliminate incorrect statements such as Salmonella producing oxygen during photosynthesis (it does not perform photosynthesis) and being Gram-positive or cocci-shaped, which are not characteristics of Salmonella.